The type or namespace name 'SalesOrderServiceClient' could not be found

Hi guys,

I am trying to expose SO using C#. I want to create sales orders in Ax2012 using a .net application. When I started writing code in C# I was getting error of missing type or namespace.

Error 1 The type or namespace name 'SalesOrderServiceClient' could not be found (are you missing a using directive or an assembly reference?) c:\users\mactoresadmin.trendsutra\documents\visual studio 2013\Projects\WindowsFormsApplication1\WindowsFormsApplication1\Form1.cs 15 9 WindowsFormsApplication1

Below are the references that I am using in my application:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

Please suggest a solution.